304奥氏体不锈钢在液态Pb-Bi合金中的空蚀行为

Cavitation erosion behavior of 304 austenitic stainless steel in Pb-Bi eutectic alloy

利用超声波空蚀试验装置研究了304奥氏体不锈钢母材及焊缝在550℃液态铅铋合金中的空蚀行为。通过扫描电子显微镜(SEM)观察不同空蚀时间后母材和焊缝的表面形貌,利用原子力显微镜(AFM)分析试样腐蚀后的表面粗糙度。结果表明,随着空蚀时间的增加,母材和焊缝表面的空蚀破坏越严重。焊缝由于存在成分偏析和组织不均匀等问题是空蚀过程中的薄弱区域。整个空蚀过程中,母材表面的粗糙度从0.098μm增加到0.460μm,焊缝表面的粗糙度从0.117μm增加到0.599μm。

The cavitation erosion behaviors of 304 austenitic stainless steel base metal and welded joint had been investigated in Pb-Bi eutectic alloy at 550 ℃ with an ultrasonic vibratory instrument. The surface morphology of the base metal and welded joint after different cavitation erosion at different time was observed by a scanning electron microscopy( SEM),the surface roughness of the samples after cavitation erosion was analyzed by an atomic force microscopy( AFM). The results indicated that the cavitation damage on the surface of base metal and welded joint was more serious with cavitation time being increased. With characters of the structure inhomogeneity and composition segregation,welded joint had the weak zone in the structural material. During the cavitation erosion process,the surface roughness of the base metal increased from0. 098 μm to 0. 460 μm,and the surface roughness of the welded joint increased from 0. 117 μm to 0. 599 μm.